This invention relates to a lightweight aircraft and more particularly to an ultralightweight aircraft having a novel propeller assembly. It further relates to a novel mounting system for the propeller and engine for such an aircraft.
This invention is a novel improvement over applicant's prior copending application, Ser. No. 213,458, filed Dec. 5, 1980, which issued as U.S. Pat. No. 4,382,566 on May 10, 1983, the disclosure of which is hereby incorporated in its entirety. That application shows a novel aircraft design in which the propellers were mounted for rotation about the principal longitudinal load-carrying structural member. The propellers were further positioned between the wing structure and the tail rudder and elevator assembly. This is a aerodynamically sound and lightweight design. It does not require additional structure for the prime mover separate from the principal longitudinal member. Additional structure can add unnecessary weight and cost to an ultralight aircraft. Thus, ultralightweight aircraft in the past have been affordable and maintainable by only a limited number of persons.
It is further necessary that the propeller and engine be so mounted as to minimize vibrational effect on the structural members. In addition to weakening these members and possibly damaging the propeller and engine, these vibrations can be distracting to the pilot of the aircraft or, at the least, be discomforting. The mounting system further should be simple of manufacture and easy to assemble. This is particularly important as these ultralightweight aircraft frequently are manufactured and sold in kit form, thus necessitating a design which is easy for the layman to assemble and disassemble. Further, the design should be such that the propeller and/or the engine can be easily removed for repair or replacement. It is also desirable that the mounting system be able to be securely attached to the longitudinal member.